Even if some major elements like P and Mn sign ores such as iron ore of Lorraine or the ores of the Pyrenees, the major elements are not enough to trace the chemical signature of an ore, the use of the traces elements. These archaeological samples being heterogeneous a total analysis of the sample is essential. Moreover in order to distinguishing the most areas possible, a maximum of elements must be analyzed (Sc, Co, Ni, Rb, Cs, Ba, Ce, Sm, Eu, Yb, Hf, Th, U, Co, Ni). Analysis by ICP-MS (Inductively Coupled Plasma Mass Spectrometry) seemed to us the most adapted to these problems (sensitivity, precision, analyze multi elementary). One of the difficulties of this method is to find a procedure of mineralisation which allows the complete dissolution of the sample. We chose to carry out an acid mineralisation on sand bath (220°C) in Teflon bombs. This method allows a complete dissolution of the sample while bringing a weak contamination and to have a good detection limit. In the first time the efficiency of the dissolution procedure was checked by analyzing standards. However, the absence of standard for slags and the limited number of certified elements obliged us to compare the results obtained by ICP-MS with those of another method. The INAA (instrumental neutron activation analysis) was selected because the current use of this purely instrumental method in the field of geochemistry in made a technique of reference. The values obtained by INAA were used as reference and were compared with the ICP-MS values determined.
Techniques used :
Instrumental neutron activation analysis